3DJH
),/7(56
A filter must be in place any time the unit is in opera-
tion. The filter may be located in the unit (optional
kit) or installed in a return air grille. Ask your dealer
to show you the filter location. The filter should be
inspected monthly and cleaned when necessary to
assure proper furnace operation.
Filters used inside the 90UGF series unit are available
from Lennox and must be ordered separately. These
foam filters may be cleaned for reuse. If replacement
is necessary, order Lennox part no. 31J81 for 14 X
25 (356 X 635mm) filter for 90UGF--50 and --75 units
and P--8--7831 for 20 X 25 (508 X 635mm) filter used
with 90UGF--100 and --125 units. Use the following
procedure to clean filter. Refer to figure 1.
In--Unit Filter with Bottom Return Air
1 -- Turn off electric power to furnace.
2 -- Remove blower access panel.
3 -- Remove filter by pressing side filter clips and
pulling filter up and out. See figure 4.
),*85(
%27720 5(7851 ),/7(5 ,167$//$7,21
)851$&(
%$6( %27720
5($5 ),/7(5 &/,3
5(7851 $,5 23(1,1*
6,'( ),/7(5 &/,36
)851$&(
)5217
)851$&(
%$&.
4 -- Clean filter with cold water and a mild soap. Di-
rect water through filter in the opposite direction
of air flow. Remove all soap residue.
5 -- Allow filter to dry then spray with filter handicoat-
er (P--8--5069), available from your Lennox dealer,
prior to reinstallation.
6 -- Place filter in bottom of blower compartment be-
neath rear filter clip. Press down on filter sides.
Filter clips flex, allowing filter to snap into place.
7 -- Replace blower access panel.
:$51,1*
%ORZHU GRRU PXVW EH VHFXUHO\ LQ SODFH ZKHQ
EORZHU DQG EXUQHUV DUH RSHUDWLQJ *DV IXPHV
ZKLFK FRXOG FRQWDLQ FDUERQ PRQR[LGH FDQ EH
GUDZQ LQWR OLYLQJ VSDFH UHVXOWLQJ LQ SHUVRQDO LQMX
U\ RU GHDWK
In--Unit Filter with Side Return Air (See Figure 5)
1 -- Turn off electric power to furnace.
2 -- Locate the filter door of the filter rack assembly.
3 -- Using the filter door pins, pull filter door, with fil-
ter attached, out of filter rack assembly. Remove
filter door from filter by pulling up on securing
tabs.
4 -- Clean filter with cold water and a mild soap. Di-
rect water through filter in the opposite direction
of air flow. Allow filter to dry, then spray with filter
handicoater, available from your Lennox dealer,
prior to reinstallation.
5 -- Position filter door on end of filter so that the
thumb tab side of the filter door is away from the
furnace. Check for correct air flow position.
Squeeze thumb tabs to secure filter to door.
6 -- Guide filter and filter door into the filter rack
installed on side of furnace. Push door into filter
rack until secure.
),*85(
5(029,1* 5(3/$&,1* ),/7(5 '225
),/7(5 '225
),/7(5
),/7(5 '225
3,1
7$%
7$%
),/7(5 '225
3,1
6($621$/ ,163(&7,216
A qualified service technician should inspect the com-
plete system each season (heating and cooling). The
following maintenance procedures should be con-
ducted by a qualified service technician. Do not at-
tempt to service the unit in any way.
During a seasonal check the service technician will in-
spect the indoor blower, the burner flame and the
venting system.
Venting System
Annually (before heating season) inspect furnace
venting system, heat exchanger and burners for
corrosion, deterioration, or deposits of debris. Re-
move any obstructions.
Inspect furnace venting system to make sure it is in
place, physically sound, and without holes, corro-
sion, or blockage. Vent connector must be in correct
position, sloped upward and be physically sound
without holes or excessive corrosion.
Inspect furnace return air duct connection to ensure
duct is sealed to the furnace and terminates outside
the space containing the furnace.
